Investments (Narrative) (Details) (USD $)	3 Months Ended		12 Months Ended
	Mar. 31, 2014	Mar. 31, 2013	Dec. 31, 2013	Dec. 31, 2008	Aug. 31, 2007
Unrealized gain (loss) on investment under fair value method	$ 0	$ 1,100,000
kaleo
Total cash invested in private company				7,500,000
Ownership interest percentage	20.00%
Carrying value	37,100,000		37,100,000
Unrealized gain (loss) on investment under fair value method	0	1,100,000
Weighted average cost of capital	45.00%	55.00%	55.00%
Basis point decrease of weighted average cost of capital assumption	5.00%
Basis point increase of weighted average cost of capital assumption	5.00%
Increase in fair value from five hundred point decrease in weighted average cost of capital assumption	7,000,000
Decrease in fair value from five hundred point increase in weighted average cost of capital assumption	6,000,000
Harbinger Fund
Investment carrying value	2,600,000		2,800,000
Cost-method investment, OTTI	200,000
Total withdrawal proceeds received		200,000
Alleghany And Bath County, Virginia
Investment carrying value	$ 5,900,000		$ 5,900,000